Sökning: "degenerate parabolic"

Visar resultat 6 - 9 av 9 avhandlingar innehållade orden degenerate parabolic.

1. 6. Selected Topics in Mathematical Modelling: Machine Learning and Tugs-of-War

   Författare :Carmina Fjellström; Kaj Nyström; Andrea Pascucci; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Machine learning; Neural networks; LSTM; Financial forecasting; Time series analysis; Stochastic gradient descent; Diffusion map; Dimension reduction; Tug-of-war games; Fractional heat operator; Mean value property; Infinity fractional heat operators; Dynamic programming principle; p-Laplacian; Infinity Laplacian; Kolmogorov equation; Stochastic games; Viscosity solutions; Tillämpad matematik och statistik; Applied Mathematics and Statistics;

   Sammanfattning : This thesis concerns selected topics in mathematical modelling, namely in machine learning and stochastic games called tugs-of-war. It consists of four scientific articles. The first and second are about machine learning topics, while the third and fourth articles are about tug-of-war games. LÄS MER

3. 7. Automorphic forms and string theory: Small automorphic representations and non-perturbative effects

   Författare :Henrik Gustafsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; instantons; automorphic forms; automorphic representations; Eisenstein series; U-duality; non-perturbative effects; string theory;

   Sammanfattning : This compilation thesis stems from a project with the purpose of determining non-perturbative contributions to scattering amplitudes in string theory carrying important information about instantons, black hole quantum states and M-theory. The scattering amplitudes are functions on the moduli space invariant under the discrete U-duality group and this invariance is one of the defining properties of an automorphic form. LÄS MER

4. 8. Boundary Behavior of p-Laplace Type Equations

   Författare :Benny Avelin; Kaj Nyström; Steve Hofmann; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; p-Laplace; Boundary Harnack inequality; A-harmonic; Ahlfors regularity; NTA-domains; Martin boundary; Reifenberg flat; Approximable by Lipschitz graphs; Subelliptic; Carleson estimate; Mathematics; Matematik;

   Sammanfattning : This thesis consists of six scientific papers, an introduction and a summary. All six papers concern the boundary behavior of non-negative solutions to partial differential equations.Paper I concerns solutions to certain p-Laplace type operators with variable coefficients. LÄS MER

5. 9. Convection-diffusion-reaction models of sedimentation : Numerical approximation, analysis of solutions and inverse problems

   Författare :Julio Careaga; Matematik LTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The core of this Doctoral thesis is mainly based in the studies of one-dimensional initial-boundary value problems, which are given by a single non-linear hyperbolic partial differential equation (PDE) with non-convex flux function, or by a system of strongly degenerate parabolic PDEs, for the simulation of sedimentation processes of solid particles immersed in a fluid. Particular attention is paid to the case of settling in vessels with varying cross-sectional area. LÄS MER